The invention relates to a mobile terminal that captures a position by utilizing satellites for GPS (Global Positioning System).
The GPS is a system for deducing a present precise position from pieces of information on a trajectory and a time by receiving radio waves transmitted from a plurality of artificial satellites orbited at an altitude of approximately 20,000 km in the sky.
At the present, the GPS is utilized in a great variety of fields ranging from a car navigation system for an automobile to a location survey technology.
As this type of technology, there is a satellite navigation system, as well as being a antenna device used for a car navigation utilizing the GPS. The satellite navigation system for detecting multipass waves by using a dextrorotatory circularly polarized wave antenna and a levorotatory circularly polarized wave antenna and by comparing an output level of the dextrorotatory circularly polarized wave antenna with an output level of the levorotatory circularly polarized wave antenna.
Further, the GPS is used to get position information when doing emergency call by the cellular phone.
For example, in the event of dialing emergency call to the police by utilizing the cellular phone, the police side grasps neither where the cellular phone is located nor where an accident happens, accordingly. Therefore, this might cause a hindrance on the occasion that the policeman is dispatched to the accident spot. For obviating this problem, there is a system for utilizing the GPS for the emergency call by a contrivance that the cellular phone can notify of its positional information.
Moreover, in addition to the emergency call, there will be provided other portable navigation services utilizing the positional information, such as displaying a restaurant closest to a position where the user himself or herself exists, and so on.
In a case where the cellular phone has a built-in GPS function, however, a position of installing the antenna can not be fixed unlike the automobile. Namely, the cellular phone is unable to keep a fixed direction, and hence the antenna built in the cellular phone points in unspecified directions.
Accordingly, the antenna of the cellular phone does not necessarily receive the radio waves from the GPS satellite in a preferable position and a preferable direction.
Therefore, in case a person carries the cellular phone while attaching it to the waist, there is an instance of measuring the position with the cellular phone attached to the shoulder by separating the antenna unit.
Given herein is an explanation of types of the antennas.
A patch antenna is given as what is typical of the GPS antenna. This patch antenna has, as shown in FIG. 6, directional only in an upper adverse side direction, and is capable of receiving the waves directly from the satellite with a high sensitivity.
Further, a chip antenna is typical of the antenna for the cellular phone. This chip antenna has a radiation pattern that, as illustrated in FIG. 7, spreads in all directions. Moreover, the chip antenna is extremely small-sized. Therefore, the chip antenna is excellent as the antenna for the cellular phone and is capable of receiving the GPS radio waves and the waves for communications of the cellular phone without changing the antenna.